About this Journal Submit a Manuscript Table of Contents
Arthritis
Volume 2014 (2014), Article ID 121069, 5 pages
http://dx.doi.org/10.1155/2014/121069
Research Article

A Technique of Predicting Radiographic Joint Line and Posterior Femoral Condylar Offset of the Knee

Department of Orthopaedics and Trauma, The Royal Infirmary of Edinburgh, Little France, Edinburgh EH16 4SA, UK

Received 22 April 2013; Revised 11 December 2013; Accepted 27 December 2013; Published 11 February 2014

Academic Editor: Charles J. Malemud

Copyright © 2014 Nicholas D. Clement et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose. To describe a reliable method of predicting native joint line and posterior condylar offset (PCO) using true lateral digital radiographs of the distal femur. Methods. PCO was measured relative to a line drawn parallel to the posterior cortex of the distal femur and the joint line was measured from the posterior condylar flare to the articular surface. A ratio was then calculated for these measurements relative to the width of the femur at the level of the flare. Two independent observers measured PCO and joint line ratio for 105 radiographs of the different knees and one repeated these measurements after one week. Results. There was a significant correlation between the width of the femoral diaphysis at the level of the posterior condylar flare with joint line ( ) and PCO ( ). Joint line and PCO could be predicted within 4 mm and 2 mm, respectively, using the identified ratio between the width of the femoral diaphysis at the level of the posterior condylar flare with measured joint line and PCO. The inter- ( ) and intra- ( ) observer reliability for these ratios were high. Conclusion. These ratios could be used to predict the native joint line and PCO.